Femoral compression device with progressive pressure device

ABSTRACT

A femoral compression device ( 1; 41; 51; 61 ) for compressing a femoral artery of a patient is provided. The femoral compression device ( 1; 41; 51; 61 ) comprises a pressure device ( 7; 21; 31; 42; 55; 62 ), a compression member ( 8; 43; 56; 65 ) for compressive bearing against a puncture site, a base portion ( 3; 44; 52 ) provided with two opposing extensions ( 4, 5; 45, 46; 53, 54 ), to the ends of which a belt ( 6 ), which is adapted to be arranged around the patient&#39;s body, can be fixed. According to the invention, the pressure device ( 7; 21; 31; 42; 55; 62 ) is characterized by non-uniform overall action constants, such that when a low compression pressure is applied, the pressure device ( 7; 21; 31; 42; 55; 62 ) exhibits a small action constant, and when a high compression pressure is applied, the pressure device ( 7; 21; 31; 42; 55; 62 ) exhibits a large action constant.

FIELD OF THE INVENTION

[0001] The present invention relates generally to a femoral compressiondevice comprising a pressure device that provides the pressure forcompressing a femoral artery of a patient, and more particularly to afemoral compression device comprising a pressure device beingcharacterized by having a non-uniform action over its operating range.

BACKGROUND OF THE INVENTION

[0002] The present invention is a modification of the femoralcompression devices disclosed in the patents U.S. Pat. No. 5,307,811 andEP 0 462 088 B1, which are assigned to the present assignee and whichclaim priority from SE 9002077 and SE 9003271. A femoral compressiondevice according to these publications comprises basically a pressuredevice for compressive bearing against a puncture site at a femoralartery of a patient (the puncture being made to access the patient'svascular system for various procedures), a belt adapted to be fixedaround the patient's body, and a base plate supporting the pressuredevice and being provided with two extensions. The pressure deviceaccording to these publications is a pneumatic device in the form of aninflatable air cushion or balloon, different embodiments of which havealso been disclosed in U.S. Pat. No. 5,542,427, WO 94/05221, WO 98/34547and U.S. application Ser. Nos. 09/355,736, 10/209,974 and 10/235,859,which all are assigned to the present assignee. In U.S. application Ser.No. 10/322,809, which also is assigned to the present assignee, thepressure device is instead in the form of a coil spring, which isconnected to a compression member being adapted for compressive bearingagainst a puncture site at a femoral artery. All of the documents citedin this paragraph are incorporated herein by reference.

[0003] During use of a femoral compression device according to thepublications mentioned above, the inflatable air cushion or compressionmember is positioned over a femoral artery of a patient, and the belt,which extends from the end of the first extension, around the patient'sbody and to the end of the second extension, is tightened. Then, thepressure device is actuated to thereby apply compression pressure suchthat the femoral artery is compressed in order to prevent bleedingthrough a puncture hole being made in the artery wall. Usually, thecompression procedure involves a short initial compression (for 1-5minutes) at a relatively high pressure (usually above the systolicpressure) followed by a longer post-compression (for 3-120 minutes) at alower pressure (usually below the diastolic pressure). Consequently, afemoral compression device and its accompanying pressure device must beable to operate within a fairly large pressure range, going from about30 mmHg to about 250 mmHg. Because of this large operating range and forreasons to be discussed below, the pressure device of the known femoralcompression devices can be improved.

SUMMARY OF THE INVENTION

[0004] For the sake of clarity, the description of the present inventionwill be mainly directed to a pressure device in the form of a mechanicaldevice, such as one or several coil springs or other types of springs,but it should be understood that the principles according to theinvention are equally applicable to a pressure device in the form of apneumatic means, such as an inflatable air cushion or balloon, or acombination of mechanical and pneumatic pressurizing component(s), orother types of pressure devices.

[0005] A common feature of the pressure device according to thepublications listed above —whether it is in the form of a pneumaticdevice or in the form of a mechanical, spring-type device—is that thepressure device, at least within its main operating range, can becharacterized by a single action constant. For a pressure device in theform of a coil spring this action constant is the so-called springconstant, which, according to Hook's law, gives the force required tocompress the spring a certain distance or, equivalently, the forceexerted by the coil spring for a given compression.

[0006] As indicated above, especially the post-compression period can berather lengthy, and during this post-compression period it frequentlyhappens that the patient moves. Such movements, either they areintentional or unintentional, will more or less unavoidably lead to achange in the compression length of the pressure device and therefore toa change in the compression pressure applied, which, in turn, can leadto unnecessary bleeding.

[0007] In this respect, a femoral compression device should therefore be“forgiving” regarding movements of the patient, i.e. the compressionpressure should not change drastically for small changes in thecompression of the pressure device in question. For a pressure device inthe form of a coil spring, a perhaps natural way to address this problemwould be to use a coil spring having a small spring constant. However,to use a coil spring characterized by a small spring constant impliesthat a rather long coil spring has to be provided, in order to be ableto apply the necessary large compression pressure required especiallyduring the initial compression phase. The use of such a long coil springentails at least two disadvantages: (1) a long regulating range of theactuation means that adjusts the compression length of the coil spring,and (2) a large construction space has to be provided to accommodate thecoil spring.

[0008] If the actuation means is in the form of a handle which a userturns to compress the coil spring, the first disadvantage implies thatthe handle has to be rotated several turns before the required largeinitial compression pressure is applied on the femoral artery. Having inmind that the bleeding from the femoral artery usually is quite severe,an adjustment that takes an unduly long time is a significantdisadvantage that may lead to unnecessary bleeding.

[0009] Especially if the coil spring is arranged essentiallyperpendicular to the base plate of the femoral compression device, thesecond disadvantage implies that the femoral compression device isrendered a design that occupies a lot of storing space and which is alsoawkward to use. And even if the coil spring is accommodated in a recesswithin one of the two extensions of the femoral compression device, sucha long recess may weaken the overall strength of the femoral compressiondevice and may also lead to difficulties in the manufacturing of thefemoral compression device.

[0010] The object of the present invention is therefore to provide afemoral compression device being provided with a pressuring device thatallows movements by the patient without leading to a drastic change inthe compression pressure applied on the femoral artery. At the sametime, the pressure device should allow a short regulating range for theactuation means that regulate the compression pressure, so that a quickadjustment can be achieved. Further, the adjusting means should notoccupy an excessive amount of the available construction space.

[0011] The above-mentioned object is achieved by a femoral compressiondevice which is provided with a pressure device being characterized by anon-uniform action, such that a large action constant is provided when ahigh compression pressure is required and a small action constant isprovided when a low compression pressure is required. In a firstembodiment of the present invention, the pressure device is provided inthe form of at least two coil springs having different spring constants.In the first embodiment, the coil springs are arranged such that thecoil springs essentially operate in sequence, whereas a secondembodiment discloses an arrangement where at least two coil springsoperate concurrently. In a third embodiment, the pressure device is inthe form of a single coil spring, which is characterized by having atleast two portions with different spiral pitches and thereby differentspring constants. In a fourth embodiment of the present invention, thepressure device is in the form of a leaf spring, the active length ofwhich can adjusted and which has such a shape that different springconstants are obtained for different active lengths. A fifth embodimentdiscloses a combination of a mechanical pressurizing means and apneumatic pressurizing means.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIG. 1 is a schematic cross-sectional view of a femoralcompression device according to the present invention which is attachedto the body of a patient.

[0013]FIG. 2 is a cross-sectional view of the pressure device of thefemoral compression device of FIG. 1 in a first state.

[0014]FIG. 3 is a cross-sectional view of the pressure device of FIG. 1in a second state.

[0015]FIG. 4 illustrates a second embodiment of a pressure deviceaccording to the present invention.

[0016]FIG. 5 illustrates a third embodiment of a pressure deviceaccording to the present invention.

[0017]FIG. 6 illustrates an alternative arrangement of a pressure deviceaccording to the present invention within a femoral compression device.

[0018]FIG. 7 illustrates a fourth embodiment of a pressure deviceaccording to the present invention.

[0019]FIG. 8 illustrates a fifth embodiment of a pressure deviceaccording to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020]FIG. 1 illustrates schematically how a femoral compression device1 according to the present invention is attached to the body of apatient in order to apply compression pressure on a femoral artery 2 inwhich a puncture hole has been made. The femoral compression device 1comprises basically a base plate 3 provided with two opposing extensions4 and 5, to the ends of which a belt 6, which is arranged around thepatient's body, is fixed. The femoral compression device 1 comprisesfurther a pressure device 7 (not shown in the figure), which isconnected to a compression member 8 being adapted for compressivebearing against the puncture site. The pressure device 7 is accommodatedin a housing 9 and can be actuated by a knob or handle 10.

[0021]FIG. 2 is a cross-section of the pressure device 7 of thecompression device 1 illustrated in FIG. 1. Although somewhat difficultto discern from FIG. 2, the pressure device 7 is in this firstembodiment of the present invention in the form of two coil springs 11and 12. The first coil spring 11 has a first length and is characterizedby a first spring constant, while the second coil spring 12 has a secondlength and is characterized by a second spring constant. In thisspecific embodiment, the first length is longer than the second lengthand the first spring constant is smaller than the second springconstant. The first and second coil springs 11, 12 are arranged suchthat the respective lower ends of the first and second coil springs 11,12 are attached to the compression member 8, with the second coil spring12 being positioned inside the first coil spring 11. An adjusting screw13, whose upper end is connected to the handle 10, is threaded throughan internally-threaded washer 14, which bears against the upper end ofthe first coil spring 11. The washer 14 can slide within housing 9 butis prevented from turning within the housing 9.

[0022] Herein, the terms “small” and “large” spring constants,respectively, refer to how easy a spring being characterized by acertain spring constant is compressed. A small spring constant impliesthat the spring is relatively easily compressed, or that the spring fora certain compression exerts only a relatively small amount of force. Alarge spring constant, on the other hand, implies that a relativelylarge amount of force is required to compress the spring, or that thespring for a certain compression exerts a relatively large amount offorce. In practise, suitable specific values for the spring constantscan be determined from tests or calculations, and can also be tailoredto different fields of application, such as different body constitutionsof the patients on which a femoral compression device is to be attached.The corresponding definitions also apply for the more general terms“small” and “large” action constants, respectively.

[0023] In FIG. 2, the pressure device 7 is shown in a state where thewasher 14 presses only against the first coil spring 11, which is onlyslightly compressed. Since there is no force acting on the second coilspring 12, the second coil spring 12 is completely uncompressed and theoverall action of the pressure device 7 is given by the first coilspring 11 only. If the first spring constant is relatively small, thisstate would therefore correspond to a situation in which only a smallamount of compression pressure is applied on a femoral artery, whichaccording to the above would be during the post-compression phase of thecompression treatment of a patient.

[0024] To apply more compression pressure—as is required during theinitial compression phase—the handle 10 is turned, which causes thewasher 14 to move downwards along the threads of the adjusting screw 13.In the position shown in FIG. 3, the washer 14 compresses both the firstcoil spring 11 and the second coil spring 12. Consequently, the overallaction constant now larger, and this state would therefore correspond toa situation in which a rather large amount of compression pressure isapplied on a femoral artery.

[0025] In the first embodiment of a pressure device according to thepresent invention, the coil springs 11, 12 have been arranged such thatfor a low compression pressure the action of the femoral compressiondevice 1 is governed by the first coil spring 11 only, while for ahigher compression pressure the action is mainly determined by thesecond coil spring 12, which has the larger spring constant. There aremany ways to arrange two (or more) coil springs. The coil springs could,for example, be arranged side by side, or the coil springs could beaccommodated in one or both of the extensions. The coils springs couldbe actuated by a common actuation means, such as the handle 10 shown inFIGS. 2 and 3, or more actuation means could be provided, with eachactuation means being connected to a single coil spring.

[0026] A principally somewhat different way of obtaining a non-uniformoverall action for the pressure device is illustrated in FIG. 4, where asecond embodiment of a pressure device 21 comprises a first coil spring22 being characterized by a first spring constant and a second coilspring 23 being characterized by a second spring constant. In thisembodiment, one end of the first coil spring 22 is connected to one endof the second coil spring 23. With this arrangement, the overall actionof the pressure device 21 is governed by both the first and secondspring constants throughout the whole operating range of the pressuredevice 21.

[0027] A third embodiment of a pressure device 31 is illustrated in FIG.5. In this embodiment, the pressure device 31 consists of a single coilspring 31, which has two portions, a first portion 32 and a secondportion 33. As can be seen in the figure, the first and second portions32, 33 have different spring pitches, which, in turn, implies that thefirst and second portions 32, 33 are characterized by different springconstants. The overall action of the pressure device 31 illustrated inFIG. 5 is therefore essentially the same as the action obtained by thepressure device 21 illustrated in FIG. 4. The same effect could also beachieved by a coil spring having two coil portions with differentstiffness, which could be obtained by different coil thicknesses ordifferent materials in the different portions. In particular from FIG. 4and FIG. 5 it should be apparent that three or more coil springs couldbe provided after each other, or that a single coil spring having morethan two portions with different spring constants could be provided, orany combination thereof.

[0028] As mentioned above, a pressure device in the form of one orseveral coil springs could be accommodated in one of the extensionsprovided on the base plate of a femoral compression device. In FIG. 6such an arrangement is illustrated, where a compression device 41comprises a pressure device 42 in the form of a coil spring 42 of, forexample, the type illustrated in FIG. 5, i.e. the coil spring 42 has twoportions with different spring pitches and thereby different springconstants. The coil spring 42 is connected to a compression member 43being adapted for bearing against a puncture site, and a base portion44, which is provided with two opposing extensions 45 and 46, to which abelt (not shown in the figure) can be attached. The coil spring 42 ispartly arranged in one of the two extensions 46 and partly in the baseportion 44. This arrangement of the coil spring 42 makes efficient useof the available space within the extension 46 and base portion 44. Ahandle 48 is provided at the extension 46 in which the spring coil 42 isarranged, and is connected to the first end of the coil spring 42, thesecond end of which is connected to the compression member 43. Thehandle 48, which is variable along the extension 46, is provided with alocking mechanism, so that the handle 48 can be moved, against theaction of the coil spring 42, and be locked in any one of many possiblepositions along the extension 46. Alternatively, the handle can bedesigned such that the handle is infinitely variable along the extension(that is, the handle can be locked in an infinite number of positions).The compression member 43 is further provided with a guide rod 47, whichis slidable within a guide hole provided inside the base portion 44. Thepurpose of the guide rod 47 and the corresponding guide hole is toprovide a stable and reliable movement of the compression member 43. Theguide rod 47 and the guide hole can preferably have non-cylindricalcross-sections, which prevents the guide rod 47 from rotating inside theguide hole.

[0029]FIG. 7 shows a fourth embodiment of a pressure device according tothe present invention. Here, a femoral compression device 51 comprisesbasically a base portion 52 provided with two opposing extensions 53,54, a pressure device 55 and a compression member 56 provided with a rod57, which is connected to the pressure device 55. In this embodiment,the pressure device 55 is in the form of a leaf spring 55 and is partlyaccommodated within a recess in one of the extensions 54. By moving ahandle 58, a user can adjust the active length of the leaf spring 55,such that the compression pressure exerted by the compression member 56on a puncture site at a femoral artery can be controlled. As is seen inthe figure, the leaf spring 55 is curved, with a non-uniform curvature.The leaf spring 55 will therefore exhibit a non-uniform spring constant,with a comparatively larger spring constant for a small active length(when the handle 58 has been moved to the left in FIG. 7) and with acomparatively smaller spring constant for a long active length (when thehandle 58 has been moved to the right in FIG. 7).

[0030] As mentioned above, the principles of the invention are notrestricted to a mechanical pressure device, such as coil or leafsprings, but are equally applicable to other types of pressuredevice(s). In FIG. 8 an arrangement is shown, where a femoralcompression device 61 is provided with a pressure device 62 whichcomprises a coil spring 63 and an inflatable air cushion 64, whose lowerportion constitutes a compression member 65 adapted for compressivebearing at a puncture site. By choosing a coil spring 63 beingcharacterized by a suitable spring constant and an inflatable aircushion 64 being characterized by a suitable action constant, thepressure device 62 can be provided with an overall action with which itis possible to obtain a small action constant when a low compressionpressure is required and a large action constant when a high compressionpressure is required.

[0031] Although the present invention has been described with referenceto specific embodiments, also shown in the appended drawings, it will beapparent for those skilled in the art that many variations andmodifications can be done within the scope of the invention as describedin the specification and defined with reference to the following claims.For example, the invention can be applied to compression devices forother arteries or vessels.

What is claimed is:
 1. A compression device adapted to be arranged atthe body of a patient and for compressing a vessel, comprising apressure device, and a compression member, which receives pressure fromthe pressure device, for compressive bearing against a puncture site,wherein the pressure device is characterized by a non-uniform overallaction constant, such that when a low compression pressure is applied,the pressure device exhibits a small action constant, and when a highcompression pressure is applied, the pressure device exhibits a largeaction constant.
 2. A compression device according to claim 1, whereinthe pressure device is in the form of at least two coil springs beingcharacterized by having different spring constants.
 3. A compressiondevice according to claim 1, wherein the pressure device is in the formof a coil spring which has at least two portions with different springpitches and thereby different spring constants.
 4. A compression deviceaccording to claim 1, wherein the pressure device is in the form of aleaf spring which has a non-uniform curvature such that different springconstants can be obtained for different lengths of the leaf spring.
 5. Acompression device according to claim 1, wherein the pressure devicecomprises mechanical pressure means and a pneumatic pressure means.
 6. Acompression device according to claim 5, wherein the mechanical pressuremeans comprises at least one spring.
 7. A compression device accordingto claim 5, wherein the pneumatic pressure means comprises an inflatableair cushion.
 8. A compression device according to claim 2, wherein theat least two coil springs are provided between the compression memberand a handle, which can be operated to adjust the compressions of the atleast two coil springs.
 9. A compression device according to claim 3,wherein the coil spring is provided between the compression member and ahandle, which can be operated to adjust the compression of the coilspring.
 10. A compression device according to claim 4, wherein thecompression device also comprises a handle, which can be operated toadjust the active length of the leaf spring.
 11. A compression deviceaccording to claim 6, wherein the at least one spring is providedbetween the pneumatic pressure means and a handle, which can be operatedto adjust the compression of the spring.
 12. A compression deviceaccording to claim 8, wherein the first ends of the at least two coilsprings are connected to the compression member and the springs,together with an adjusting screw, are provided in a housing, the upperend of the adjusting screw being connected to the handle and theadjusting screw being threaded through a washer, which can bear againstthe second ends of the at least two coil springs, so that, by turningthe handle, the washer moves along the adjusting screw to thereby adjustthe compressions of the coil springs.
 13. A compression device accordingto claim 9, wherein the first end of the coil spring is connected to thecompression member and the coil spring, together with an adjustingscrew, is provided in a housing, the upper end of the adjusting screwbeing connected to the handle and the adjusting screw being threadedthrough a washer, which can bear against the second end of the coilspring, so that, by turning the handle, the washer moves along theadjusting screw to thereby adjust the compression of the coil spring.14. A compression device according to claim 8, further comprising a baseportion provided with two opposing extensions, to the ends of which abelt, which is adapted to be arranged around the patient's body, can befixed, and wherein the first ends of the at least two coil springs areconnected to the compression member, the coil springs extend through thebase portion and at least partly into one of the extensions, and thesecond ends of the at least two coil springs are connected to thehandle, which is slidable along said extension and which is lockable ata desired position, so that the compressions of the coil springs can beadjusted by moving the handle.
 15. A compression device according toclaim 9, further comprising a base portion provided with two opposingextensions, to the ends of which a belt, which is adapted to be arrangedaround the patient's body, can be fixed, and wherein the first end ofthe coil spring is connected to the compression member, the coil springextends through the base portion and at least partly into one of theextensions, and the second end of the coil spring is connected to thehandle, which is slidable along said extension and which is lockable ata desired position, so that the compression of the coil spring can beadjusted by moving the handle.
 16. A compression device according toclaim 1, wherein the compression member is configured for compressivebearing against a puncture site in a femoral artery.
 17. A compressiondevice according to claim 1, further comprising a base portion providedwith two opposing extensions, to the ends of which a belt, which isadapted to be arranged around the patient's body, can be fixed.